1. Field of the Invention
The invention relates to an apparatus for utilizing the waste heat of an internal combustion engine in a vehicle, in particular in a railway vehicle, in which the apparatus has an exhaust gas line for removing exhaust gases from the internal combustion engine and the exhaust gas line is thermally connected to a high-temperature side of a thermoelectric generator. The invention further relates to a process for operating an internal combustion engine in a vehicle, in particular in a railway vehicle, in which exhaust gases from the internal combustion engine are diverted off through an exhaust gas line and the waste heat from the internal combustion engine that is diverted off with the exhaust gases is fed into a high-temperature side of a thermoelectric generator, and the thermoelectric generator utilizes the waste heat to generate electrical energy.
2. Description of Related Art
An apparatus of this type and a process of this type are disclosed in US 2005/0268955 A1. As also described in this publication, the internal combustion engine may in particular be the traction motor of a vehicle, for example a railway vehicle. In particular, in this case the internal combustion engine generates energy (in particular by driving a mechanically driven electric generator) for the traction of the vehicle and optionally also for other devices on the vehicle. The internal combustion engine is usually thermally connected to at least one coolant circuit.
The invention relates in particular to the field of railway vehicles, in which much more powerful internal combustion engines typically are used than is the case with highway vehicles. The railway vehicle may in particular be a locomotive, for example a diesel-electric locomotive. However, use of the invention in other vehicles, such as ships, is also conceivable.
In the apparatus that is described in US 2005/0268955 A1, high fluctuations are encountered in the generation of electrical power by the thermoelectric generator. In particular, the electrical power of the generator is low when the internal combustion engine generates low mechanical power. The problem is intensified by the fact that the efficiency with which a thermoelectric generator generates electrical energy from heat depends, among other things, on the temperature level on the high-temperature side of the generator. When waste heat from the exhaust gas line of the internal combustion engine is used, though, the temperature of the exhaust gas varies greatly within a very wide temperature range.